Different methods have been disclosed in the art for encoding images and illustrations or making invisible engravings on different materials. Hidden images and engravings may be utilized for producing ornamental and decorative articles or alternatively they may be utilized to create security documents and holographic images.
There is still a need in the art for methods of encoding or engraving hidden images on different surfaces for the purpose of creating decorative or security articles. The hidden or engraved images ideally may be only visible when for example looked at from a certain angle or when light is shone on them from a certain position and/or angle.